High-performance starch-modified graphene oxide/epoxy nanocomposite coatings: A glimpse at cure kinetics and fracture behavior

Epoxy is a versatile resin used in different fields such as coatings, colors, colorants, and composites. Adding nano-scale fillers/additives to the epoxy has valued epoxy coatings for engineering applications, and opened the time of advanced epoxy-based nanocomposite coatings. In the present work, graphene oxide GO was chemically functionalized with starch, as a natural polymer, and added to the epoxy/amine system. Differential scanning calorimetry was utilized to assess the cure kinetics of neat epoxy and its composites containing pristine and starch-functionalized GO GO-St. Cryofractured surfaces of epoxy/GO and epoxy/GO-St nanocomposites are detected by scanning electron microscopy. Overall, the results are indicative of appropriateness of surface functionalization of GO by starch for high-performance coating applications. Hindered cure observed in the case of epoxy/GO was conquered by the attachment of starch to GO; moreover, tree-like fracture was responsible for higher fracture resistance due to starch.